Pakistan top investigative agency chief on Tuesday refused to answer tough questions over underworld don Dawood Ibrahim and 26/11 Mumbai attacks mastermind Hafiz Sayeed, both of whom are among terrorists most wanted by Indian security agencies.

Director-General of the Federal Investigation Agency (FIA), Mohsin Butt, who is part of a two-member delegation from Islamabad who is in the national capital to participate in the Interpol General Assembly refused to make any comments on the whereabouts of Dawood and Hafiz Sayeed who are believed to have been provided sanctuary by Pakistan.